IMF (music)
Encyclopedia
IMF is an audio file format
created by id Software
for the AdLib
sound card
for use in their video games. The default filename extension
is also "imf". The abbreviation stands for "id music file" or "id's music format".
The format is similar to MIDI
, in that it defines musical notes, and does not support sample
d digital audio
for sound effects. IMF files store the actual bytes sent to the AdLib's OPL2
chip, which uses FM synthesis
to produce audio output. The format is based on the AdLib command syntax, with a few modifications. Due to the limited features and relatively low sound quality, modern games no longer use IMF music.
Once extracted from a game, IMF files can be played with special sound libraries which emulate AdLib cards. One of the most popular ones is AdPlug, which can be used, for instance, through its Winamp
plugin.
in IMF format. Besides id Software, some other game developer
s like Apogee Software
also used this format to add music to their games. Games using IMF music include: Bio Menace
, Blake Stone: Aliens of Gold
, Blake Stone: Planet Strike
, Catacomb 3-D, Commander Keen 4-6
, Corridor 7
, Cosmo's Cosmic Adventure
, Duke Nukem II
, Major Stryker
, Monster Bash
, Operation Body Count
, Spear of Destiny
, and Wolfenstein 3D
.
Audio file format
An audio file format is a file format for storing digital audio data on a computer system. This data can be stored uncompressed, or compressed to reduce the file size. It can be a raw bitstream, but it is usually a container format or an audio data format with defined storage layer.-Types of...
created by id Software
Id Software
Id Software is an American video game development company with its headquarters in Richardson, Texas. The company was founded in 1991 by four members of the computer company Softdisk: programmers John Carmack and John Romero, game designer Tom Hall, and artist Adrian Carmack...
for the AdLib
AdLib
Ad Lib, Inc. was a manufacturer of sound cards and other computer equipment founded by Martin Prevel, a former professor of music and vice-dean of the music department at the Université Laval...
sound card
Sound card
A sound card is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware...
for use in their video games. The default filename extension
Filename extension
A filename extension is a suffix to the name of a computer file applied to indicate the encoding of its contents or usage....
is also "imf". The abbreviation stands for "id music file" or "id's music format".
The format is similar to MIDI
Musical Instrument Digital Interface
MIDI is an industry-standard protocol, first defined in 1982 by Gordon Hall, that enables electronic musical instruments , computers and other electronic equipment to communicate and synchronize with each other...
, in that it defines musical notes, and does not support sample
Sampling (music)
In music, sampling is the act of taking a portion, or sample, of one sound recording and reusing it as an instrument or a different sound recording of a song or piece. Sampling was originally developed by experimental musicians working with musique concrète and electroacoustic music, who physically...
d digital audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...
for sound effects. IMF files store the actual bytes sent to the AdLib's OPL2
Yamaha YM3812
The Yamaha YM3812 also known as the OPL2 is a sound chip created by Yamaha Corporation in 1985 and famous for its wide use in IBM PC-based sound cards such as the AdLib and Sound Blaster.It is backwards compatible with the OPL aka YM3526, to which it is very similar – in fact, it only adds 3 new...
chip, which uses FM synthesis
Frequency modulation synthesis
A 220 Hz carrier tone modulated by a 440 Hz modulating tone with various choices of modulation index, β. The time domain signals are illustrated above, and the corresponding spectra are shown below ....
to produce audio output. The format is based on the AdLib command syntax, with a few modifications. Due to the limited features and relatively low sound quality, modern games no longer use IMF music.
Once extracted from a game, IMF files can be played with special sound libraries which emulate AdLib cards. One of the most popular ones is AdPlug, which can be used, for instance, through its Winamp
Winamp
Winamp is a media player for Windows-based PCs and Android devices, written by Nullsoft, now a subsidiary of AOL. It is proprietary freeware/shareware, multi-format, extensible with plug-ins and skins, and is noted for its graphical sound visualization, playlist, and media library features.Winamp...
plugin.
Games
A large number of songs in id Software's games were composed by Bobby PrinceRobert Prince
Robert Prince, also known as Bobby Prince, is a composer and sound designer. He has worked as an independent contractor for several gaming companies, most notably id Software and Apogee/3D Realms....
in IMF format. Besides id Software, some other game developer
Video game developer
A video game developer is a software developer that creates video games. A developer may specialize in a certain video game console, such as Nintendo's Wii, Microsoft's Xbox 360, Sony's PlayStation 3, or may develop for a variety of systems, including personal computers.Most developers also...
s like Apogee Software
3D Realms
3D Realms is a current video game publisher and former video game developer based in Garland, Texas, United States, established in 1987...
also used this format to add music to their games. Games using IMF music include: Bio Menace
Bio Menace
Bio Menace is a 2D, side-scrolling, platform game both developed and published by Apogee Software in 1993 for DOS. It was built on a licensed version of id Software's Commander Keen game engine, and was known as Bio Hazard during production...
, Blake Stone: Aliens of Gold
Blake Stone: Aliens of Gold
Blake Stone: Aliens of Gold is a first-person shooter computer game created by JAM Productions and published by Apogee Software. It uses the Wolfenstein 3D game engine to render graphics in first person, while adding many features....
, Blake Stone: Planet Strike
Blake Stone: Planet Strike
Blake Stone: Planet Strike is the sequel to the computer game Blake Stone: Aliens of Gold, made by JAM Productions and released on October 28, 1994, by Apogee Software...
, Catacomb 3-D, Commander Keen 4-6
Commander Keen series
Commander Keen is a series of video games developed by id Software in the early 1990s. The series focuses on the adventures of Billy Blaze, an 8-year old boy who travels through space and assumes the identity "Commander Keen". The series was successful at replicating the side-scrolling action of...
, Corridor 7
Corridor 7
Corridor 7: Alien Invasion is a first-person shooter computer game developed and published by Capstone Software. It was widely ignored for its outdated Wolfenstein 3D engine, which was technologically surpassed by Doom at the time...
, Cosmo's Cosmic Adventure
Cosmo's Cosmic Adventure
Cosmo's Cosmic Adventure is a video game programmed by Todd Replogle and published by Apogee Software in 1992. It is a two-dimensional side-scrolling platform game produced for the PC platform, and features 16-color EGA graphics at 320×200 screen resolution...
, Duke Nukem II
Duke Nukem II
Duke Nukem II is a platform game developed by Apogee Software and released December 3, 1993. The game consists of four episodes , the first available as shareware...
, Major Stryker
Major Stryker
Major Stryker is a 2D vertical scrolling shooter game written for DOS, by Apogee Software .The game was originally distributed as shareware. It consists of three episodes, with only the first episode distributed as shareware, and the rest available commercially...
, Monster Bash
Monster Bash
Monster Bash is a side-scrolling platform video game developed and published by Apogee Software on 9 April 1993 for the MS-DOS PC. The game features 16-color EGA graphics and IMF AdLib compatible music. It was developed by Frank Maddin and Gerald Lindsly.The game is divided in three episodes or...
, Operation Body Count
Operation Body Count
Operation Body Count is a 1994 first-person shooter that used the Wolfenstein 3D ray casting engine. It was developed and published by Capstone Software.- Plot :...
, Spear of Destiny
Spear of Destiny (computer game)
Spear of Destiny, often also called Spear, Wolfenstein 3D: Spear of Destiny or just SoD, is a 1992 first-person shooter computer game developed by id Software and published by FormGen Corporation, and is the prequel to id Software's Wolfenstein 3D...
, and Wolfenstein 3D
Wolfenstein 3D
Wolfenstein 3D is a video game that is generally regarded by critics and gaming journalists as having both popularized the first-person shooter genre on the PC and created the basic archetype upon which all subsequent games of the same genre would be built. It was created by id Software and...
.
External links
- AdPlug, library that supports the IMF file format
- IMF Format at ModdingWiki, including detailed information on the format